Abstract: Recent progress towards understanding a strong coupling expansion for varioussuperconformal field theories in four dimensions is described. First, the caseof the maximally supersymmetric Yang Mills theory is analyzed, as well as manycalculations that can be done directly at strong coupling and matched to theAdS dual geometry. Also, this understanding is extended to other AdS dualswhere the sphere is replaced by a Sasaki-Einstein manifold. Particular emphasisis made on matching exactly part of the supergravity dual spectrum of variousof these field theories by using wave function methods.